This study describes key challenges and necessary supports related to implementation of the Common Core State Standards for Mathematics (CCSSM) identified by rural math educators in the Northeast. The research team interviewed state and district math coordinators and surveyed teachers in Maine, New Hampshire, New York and Vermont, to assess their most pressing challenges and associated needs. Key challenges included time and support for teachers to change their instructional practices to meet the CCSSM, availability of high-quality instructional materials, and opportunities for collaboration. The report was produced in response to input from the Northeast Rural Districts Research Alliance (NRDRA), one of eight research alliances working with REL Northeast & Islands. The following are appended: (1) Data and methodology; (2) State instructional leader interview protocol; (3) District instructional leader interview protocol; and (4) Teacher survey.